package com.sfac.javaSpringBoot.interceptor;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.ui.ModelMap;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/*
* 自动封装template
* 约定：目标页面的相对路径地址与path路劲保持一致
* */
@Component
public class ViewMappingInterceptor implements HandlerInterceptor {

    private final static Logger LOGGER = LoggerFactory.getLogger(ViewMappingInterceptor.class);

    @Override
    public boolean preHandle(HttpServletRequest request,
                             HttpServletResponse response,
                             Object handler) throws Exception {
        LOGGER.debug("=====ViewMappingInterceptor preHandle");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request,
                           HttpServletResponse response,
                           Object handler, ModelAndView modelAndView) throws Exception {
        //判断请求是不是返回的视图view,如果是rest接口||redirect||forward则不做处理
        if (modelAndView==null||
                modelAndView.getViewName().startsWith("redirect")||
                modelAndView.getViewName().startsWith("forward")){
            return;
        }
        //从请求中得到path
        String path = request.getServletPath();
        //判断modelMap里面是否有设置template，如果已有，则无需设置
        String template = (String) modelAndView.getModelMap().get("template");
        if (StringUtils.isBlank(template)){
            path = path.startsWith("/")?path.substring(1):path;
            modelAndView.getModelMap().addAttribute("template", path);
        }
        //在modelMap中设置template，值为path
        LOGGER.debug("=====ViewMappingInterceptor postHandle");
    }

    @Override
    public void afterCompletion(HttpServletRequest request,
                                HttpServletResponse response,
                                Object handler, Exception ex) throws Exception {
        LOGGER.debug("=====ViewMappingInterceptor afterCompletion");
    }
}
